package com.hmdp.service.impl;

import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.dto.ScrollResult;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IFollowService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.SystemConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ZSetOperations;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

import static com.hmdp.utils.RedisConstants.BLOG_LIKED_KEY;
import static com.hmdp.utils.RedisConstants.FEED_KEY;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {

    @Resource
    private IUserService userService;
    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private IFollowService followService;

    @Override
    public Result queryHotBlog(Integer current) {
        // 根据用户查询
        Page<Blog> page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取当前页数据
        List<Blog> records = page.getRecords();
        // 查询用户
        records.forEach(blog -> {
            this.queryBlogUser(blog);
            this.isBlogLiked(blog);
        });
        return Result.ok(records);
    }

    private void queryBlogUser(Blog blog) {
        Long userId = blog.getUserId();
        User user = userService.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
    }

    @Override
    public Result queryBlogById(Long id) {
        Blog blog = getById(id);
        if (blog==null){
            return   Result.fail("笔记不存在");
        }
        queryBlogUser(blog);
        isBlogLiked(blog);
        return Result.ok(blog);
    }

    private void isBlogLiked(Blog blog) {
        UserDTO user = UserHolder.getUser();
        if (user==null){
            return;
        }
        Long userId = user.getId();
        String key="blog:liked:"+blog.getId();
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        blog.setIsLike(score!=null);
    }

    @Override
    public Result likeBlog(Long id) {
        Long userId = UserHolder.getUser().getId();
        String key="blog:liked:"+id;
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());

        if (score==null){
            boolean isSuccess = update().setSql("liked = liked + 1").eq("id", id).update();
            if (isSuccess){
                stringRedisTemplate.opsForZSet().add(key,userId.toString(),System.currentTimeMillis());
            }
        }else {
            boolean isSuccess = update().setSql("liked = liked - 1").eq("id", id).update();
            if (isSuccess){
                stringRedisTemplate.opsForZSet().remove(key,userId.toString());
            }
        }

        return Result.ok();
    }

    @Override
    public Result queryBlogLikes(Long id) {
        String key="blog:liked:"+id;
//        1、查询top5点赞用户 zrange key 0 4
        Set<String> range = stringRedisTemplate.opsForZSet().range(BLOG_LIKED_KEY+id, 0, 4);
        if (range==null||range.isEmpty()){
            return Result.ok(new ArrayList<>());
        }
//        2、解析出用户id并查询
        List<Long> ids = range.stream().map(Long::valueOf).collect(Collectors.toList());
        String idStr= StrUtil.join(",",ids);
        List<User> users = userService.query().in("id", ids)
                .last("order by field(id," + idStr + ")").list();
        List<UserDTO> userDTOS = users.stream().map(user -> {
            UserDTO userDTO = new UserDTO();
            userDTO.setIcon(user.getIcon());
            userDTO.setId(user.getId());
            userDTO.setNickName(user.getNickName());
            return userDTO;
        }).collect(Collectors.toList());
        //        3、返回
        return Result.ok(userDTOS);
    }

    @Override
    public Result saveBlog(Blog blog) {
//         获取登录用户
        UserDTO user = UserHolder.getUser();
        blog.setUserId(user.getId());
        // 保存探店博文
        boolean isSuccess = save(blog);
        if (!isSuccess){
            return Result.fail("新增笔记失败");
        }
        List<Follow> follows = followService.query().eq("follow_user_id", user.getId()).list();
        follows.forEach(follow -> {
            Long userId = follow.getUserId();
            String key="feed:" + userId;
            Boolean add = stringRedisTemplate.opsForZSet().add(key, blog.getId().toString(), System.currentTimeMillis());
        });
        // 返回id
        return Result.ok(blog.getId());
    }

    @Override
    public Result queryBlogOfFollow(Long max, Integer offset) {
        Long userId = UserHolder.getUser().getId();
        String key=FEED_KEY + userId;
        Set<ZSetOperations.TypedTuple<String>> typedTuple = stringRedisTemplate.opsForZSet()
                .reverseRangeByScoreWithScores(key, 0L,max, offset,3);
        if (typedTuple==null||typedTuple.isEmpty()){
            return Result.ok();
        }
        List<Long> ids=new ArrayList<>(typedTuple.size());
        long miniTime=0;
        int os=1;
        for (ZSetOperations.TypedTuple<String> tuple : typedTuple) {
            ids.add(Long.valueOf(tuple.getValue()));
            long time = tuple.getScore().longValue();
            if (time==miniTime){
                os++;
            }else {
                miniTime = time;
                os=1;
            }
        }
        String idStr = StrUtil.join(",", ids);
        List<Blog> blogs = query().in("id", ids).last("order by field(id," + idStr + ")").list();
        blogs = blogs.stream().map(blog -> {
            queryBlogUser(blog);
            isBlogLiked(blog);
            return blog;
        }).collect(Collectors.toList());
        ScrollResult scrollResult = new ScrollResult();
        scrollResult.setList(blogs);
        scrollResult.setOffset(os);
        scrollResult.setMinTime(miniTime);
        return Result.ok(scrollResult);
    }
}
